Method and a system for transmitting encrypted control message based on mobile multimedia broadcast

1. A method for transmitting encrypted control message based on mobile multimedia broadcast, wherein, encapsulating the media data of a program and the encrypted control message in a multiplex sub-frame of a multiplex frame; setting an encrypted control message identifier in the multiplex sub-frame header of the multiplex sub-frame; a mobile multimedia system sending the media data and the encrypted control message out through the multiplex frame.

2. The method for transmitting encrypted control message according to claim 1 , wherein, the encrypted control message is encapsulated in the data segment of the multiplex sub-frame.

3. The method for transmitting encrypted control message according to claim 1 , wherein, the value of the encrypted control message identifier is used to indicate whether the multiplex sub-frame comprises the encrypted control message.

4. The method for transmitting encrypted control message according to claim 1 , wherein, the method further comprises the following process: after receiving the multiplex sub-frame, a receiver of the program judging whether the multiplex sub-frame is encapsulated with the encrypted control message according to the encrypted control message identifier, and extracting the encrypted control message if the judging result is positive.

5. The method for transmitting encrypted control message according to claim 1 , wherein, the receiver submits the extracted encrypted control message to a decryption system.

6. The method for transmitting encrypted control message according to claim 5 , wherein, the decryption system obtains the encrypted control words from the encrypted control message, and decrypts the media data with the encrypted control words.

7. A system for transmitting encrypted control message based on mobile multimedia broadcast, wherein, comprising: a sender device for encapsulating the media data of a program and the encrypted control message in a multiplex sub-frame of a multiplex frame and setting an encrypted control message identifier in the multiplex sub-frame header of the multiplex sub-frame to indicate whether the multiplex sub-frame comprises the encrypted control message.

8. The system for transmitting encrypted control message according to claim 7 , wherein, the sender device encapsulates the encrypted control message in the data segment of the multiplex sub-frame.

9. The system for transmitting encrypted control message according to claim 7 , wherein, the sender device uses the value of the encrypted control message identifier to indicate whether the sub-frame comprises the encrypted control message.

10. The system for transmitting encrypted control message according to claim 7 , wherein, the system further comprises: a receiver device for reading the encrypted control message identifier in the multiplex sub-frame header, judging whether the multiplex sub-frame header comprises the encrypted control message according to the encrypted control message identifier, extracting the encrypted control message when the encrypted control message identifier reading part has determined that the multiplex sub-frame header comprises the encrypted control message, and submitting the encrypted control message to a decryption system.